An capacitor consists of two large parallel plates of area A separated by a very

Question

An capacitor consists of two large parallel plates of area A separated by a very small distance d. This capacitor is connected to a battery and charged until its plates carry charges +Q and -Q, and then disconnected from the battery. If the separation between the plates is now doubled, the potential difference between the plates will

A) double.

B) quadruple.

C) be cut in half.

D) be cut in fourth.

E) not change.

(Please explain why)

2.)  The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart. What happens to the strength of the electric field between the plates during this process?

A) It increases.

B) It decreases.

C) It remains constant.

D) It cannot be determined from the information given.

3.) When a dielectric material is introduced between the plates of a parallel-plate capacitor and completely fills the space, the capacitance increases by a factor of 4. What is the dielectric constant of the material that was introduced?

A) 0.4

B) 1/4

C) 2

D) 4

E) None of the other choices is correct.

Explanation / Answer

(a) V= Ed

The electric field is constant.

when the distance is doubled, V doubles. so option (a) is correct

(b) E= V/d

when the distance is increased by pulling the plates apart, the electric field decreases. so option (b) is correct.

(c) k= C/Co

K=4 Co/Co

K=4

so the option (d) is correct.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.